I am about done with epoxy work but looks like once again I'm short. I have some that is probably 4-5 years old. Hardener has turned an amber color. Mostly what I have left to do is the bottom where I'm mixing it with graphite and some touch ups on the inside where a slight color won't be a problem. I mixed some up and put it on a test piece. As long as it hardens should it be fine or does it be replaced?
Amber hardener's usually not a problem. Crystallized resin can be but that's easily reversed with a warm water bath or leaving the resin in a place that's between 85° - 90° F until it re-liquifies.
It can be hard to tell either condition with the opaque plastic containers unless you use a strong flashlight to 'candle' the container (in a darkened room use the flashlight to backlight the container so you can see what's inside) while allowing the resin inside to flow around as you turn & twist it to check liquidity.
This stuff's pretty stable if kept warm & closed tight. A test batch will tell you if it's trustworthy. Be sure to arrange for proper temp during cure interval.
Ok thanks. I'm in AZ so my garage is mostly above the 85-90 mark night and day roght now. Didn't see any crystals when I did the test batch. Just wanted to make sure it wouldn't have a weaker bond. Thanks.